1. Field of the Invention
The present invention relates to a Home Audio Video interoperability (HAVi) network system, and more particularly, to a method and system for controlling a device, which is connected to a HAVi network system designed based on an IEEE1394 network, through a non-IEEE1394 network.
2. Description of the Related Art
Home Audio Video interoperability (HAVi) is a home network standard specification in which a plurality of household electronic products provided by a variety of vendors are connected to one network, and from one product, the user can control other electronic products. The products connected to a HAVi network are referred to as HAVi devices. Among the HAVi devices, a device which is in charge of controlling other devices is referred to as a control device, and the remaining devices which are controlled by the control device are referred to as controlled devices. The physical layer of the HAVi network complies with the IEEE1394 protocol, which supports asynchronous transmission and isochronous transmission. Asynchronous transmission is mainly for transmitting control data, while isochronous transmission is for Audio/Video (AV) data.
FIG. 1 is a simplified diagram of a prior art Home Audio Video interoperability (HAVi) system.
Referring to FIG. 1, HAVi devices 10 and 30 are connected to an IEEE1394 network. Reference number 10 indicates a control device which controls a controlled device indicated by reference number 30.
The control device 10 is a Full Audio Video (FAV) device having a display apparatus (not shown) and includes a Communication Media Manager (CMM) 1394 600 and a messaging system 500. The messaging system 500 delivers HAVi messages between elements, that is, between a Device Control Module (DCM) 400 and a havlet 800, or between the DCM 400 and the controlled device 30. The CMM 1394 600 enables HAVi devices to communicate HAVi messages with each other asynchronously or isochronously based on the IEEE1394 physical layer.
Also, a DCM code unit 200 is installed in the control device 100, and accordingly, the control device 10 includes the DCM 400 and a Function Control Module (FCM) 300. The DCM 400 has information capable of providing the havlet 800. The havlet 800 is an application program based on Java and is downloaded from the DCM 400 and installed in the control device 100. The havlet 800 is a Java application having a menu system for user interface and is executed on a Java Virtual Machine (JVM) 1000 through a HAVi Java Application Program Interface (HJA) 900.
A user control command, which is input through the havlet 800, is transformed into a HAVi message through the messaging system 500 and sent to the DCM 400. A control command or data corresponding to the HAVi message sent to the DCM 400 is sent to the controlled device 30 again through the messaging system 500 and the CMM 1394 600.
In the case that the control device 10 is a digital television (DTV) and the controlled device 30 is a camcorder, if a user inputs a control command for the camcorder through a menu screen, the havlet 800 makes the control command an appropriate HAVi message and sends the message to the DCM 400. The DCM 400 controls the camcorder according to the control command of the received message.
However, since the prior art HAVi network system is built based on the IEEE1394 network, even though a HAVi device is physically or logically connected to an external network, if the external network is not an IEEE1394 network, the HAVi device cannot be controlled. That is, the havlet 800 cannot operate through a non-IEEE1394 network such as Ethernet. Therefore, through a non-IEEE1394 network, the controlled device cannot be controlled.